Automatic trip mechanism for record changing phonographs



July 31, 1956 E. -w. MORTIMER AUTOMATIC TRIP MECHANISM FOR RECORD CHANGING PHONOGRAPHS 2 Sheets-Sheet 1 Filed June 1, 1950 jvveni m m M ly 3 9 E. w. MORTIMER AUTOMATIC TRIP MECHANISM FOR RECORD CHANGING PHONOGRAPHS Filed June 1, 1950 2 Sheets-Sheet 2 Mud/ am w w m I United States Patent AUTOMATIC TRIP MECHANISM FOR RECORD CHANGING PHONOGRAPHS Edmund Walter Mortimer, Swindon, England, assignor to The Garrard Engineering & Manufacturing Company, Limited, Swindon, England Application June 1, 1950, Serial No. 165,431

12 Claims. (Cl. 2741) This invention relates to automatic trip mechanism for record changing phonographs of the type in which a trip control lever is moved in accordance with the inward feed of the pick-up, or a part thereof towards the end of the playing, the arrangement being such that the movement of such lever at each playing revolution of the record is insuflicient to cause a tripping movement, Whereas when the stylus moves into the run-out groove the increased movement of the lever causes a trip releasing movement, means being provided for neutralising the movement of the trip control lever when the stylus is in the playing grooves.

The object of the present invention is to provide an improved construction of tripping mechanism which is efficient in operation when used in connection with very light pressures of the stylus with shallow record grooves which obtain on long playing records.

An aim of the invention is to provide an improved tripping mechanism in which side pressure on the stylus during the tripping operation is eliminated, thus avoiding possible damage to the record'and to sensitive pick-ups.

According to the invention in a tripping mechanism of the type set forth means are provided for automatically disconnecting the drive between the pick-up and the trip control lever on the latter performing a trip releasing movement.

The drive between the pick-up and the trip control lever may be of a frictional character and the lever may be moved in a direction at right angles to its tripping movement to break such drive on the lever making a trip releasing movement.

The movement of the trip control lever to break the drive may be elfected by raising the lever by cam means associated with the neutralising means.

The invention will be described by way of example in connection with a record changing mechanism in which the various functions at the'end of the playing of a record are controlled through a rotary cam means incorporating an interrupted gear the gap of whichv lies opposite a driving pinion during the playingof the record, and wherein meshing of the gear with the pinion is efiected by imparting an initial impulse to the interrupted gear by spring controlled means released by the tripping means.

In the accompanying drawings:

Figure l is a plan view of the invention showing only those parts of the record changer that are associated with the trip control lever.

Figure 2 is asectional elevation on line 2-2 of Figure 1.

Figure 3 is adetail view on a larger scale of the pivotal mounting of the trip control lever.

Figure 4 is a detail part-sectional elevation looking in the direction of arrow x in Figure 1.

Figures 5 and 6 are detail plan and sectional elevation of the friction pad on the trip control lever.

Figure 7 is a plan showing. the invention applied to control the driving motor and turntable brake of a phonograph.

Figure 8 is a partial elevation looking in the direction of arrow y, Figure 7.

Figure 9 is a partial elevation looking in the direction of arrow 2, Figure 7.

In carrying the invention into effect according to one convenient mode a trip control lever 1 is pivotally mounted on a vertical axis so that its free end 1a lies in the vicinity of a rotary cam 2 located on the turntable to turn therewith. The cam 2 has a radial projection 4 having a pair of cam surfaces, one 5 arranged laterally (referred to as the side cam) and the other 6 on the upper surface (referred to as the upper cam).

The side cam 5 at each revolution engages a pad 7 on the trip control lever 1 to pivot the lever sidewise as the lever moves inwardly in accordance with the movement of the pick-up 8 during playing and thus neutralises such movements and prevents an accumulated movement. It is preferred that the trip control lever 1 is only moved during the last few playing grooves so that during the major part of the playing the lever 1 offers no side resistance to the movements of the pick-up. When the stylus enters the run-out groove a quick inward movement of the trip control lever 1 is effected Which brings it to a position above the upper cam 6. The cam 6 is adapted to co-operate with a cam surface 9 on the underside of the trip control lever 1 whereby the lever is tilted. This tilting of the lever 1 is permitted by the construction of the pivot end of the lever. At such end (beyond the pivotal axis) the lever 1 is turned downwardly at 10 and then backwardly to form a short arm 11 substantially parallel to the main portion of the lever. In such short arm 11 a slot 12 is provided parallel to the lever which engages a collar 13 on a vertical spindle 14 on which the lever 1 is freely pivoted, the spindle being secured on fixed plate 14a. The main part of the lever 1 seats upon a bush 15 surrounding the spindle 14. By such arrangement the lever 1 may pivot horizontally around the spindle 14 or tilt in a vertical plane. In the normal horizontal position, of the lever 1 one end 12a of the slot 12 in the short arm 11 engages the collar 13. On its lower surface near the pivot end the trip control lever 1 is provided with afriction pad 16 which normally engages one arm 17 of a friction lever pivoted on the spindle 14 and conveniently secured to the bush 15 by which the movements of the friction lever are imparted to the trip control lever 1. The frictional drive is dependent upon the weight of the trip control lever 1 and in order to provide for some adjustment of the friction, the pad 16 is carried in a screwed stud 18 which is adjustable in the nut 19 mounted on the lever 1. A spring clip 43 is provided to hold the stud 18 against vibration.

The other arm 20 of the friction lever 17 has a pin and slot connection 21 with one arm 22 of a transmission bell crank lever which pivots on a vertical axis 23. Theother arm 24 of the transmission lever has a pin 25 which cooperates with a slotted lever 26 operatively coupled to the pick-up 8 to move in accordance therewith. The dimension and arrangement of the slot 27 in the slotted lever 26 are such-that there is lost-motion during the major portion of the playing so that the slotted lever 26 only causes a pivoting of the transmission bell crank lever 22, 24 during the latter portion of the playing. Such pivotal movement of the transmission lever causes a pivoting of the friction lever 17, 20 and, through the friction drive, an inward movement of the trip control lever 1 which movement as above mentioned is neutralised, during playing, by the side cam 5.

When the trip control lever 1 is moved rapidly by the run-out groove and the upper cam 6 becomes elfective the trip control lever 1 is tilted to vertically raise the pad 16 out of contact with the friction lever arm 17 whereby the drive to the trip control lever 1 is broken and thus side pressure on the stylus is eliminated during operation.

The tilting of the trip control lever 1 causes engagement with and lifting of a finger 23 of a lever 29 pivoted on a horizontal axis 34 This lever 29 carries a second finger 31 which moves into engagement to rock a trip lever 32 pivoted on a vertical axis 33. This trip lever 32 in its movement is adapted to actuate a latch lever 34 pivoted on a vertical axis 35 and having a detent or tooth 36 which holds an impulse lever 37 pivoted on a vertical axis 38 with its spring 39 stressed. When the latch lever 34 is released by the trip lever 32 impulse lever 37 swings over under action of the spring 39 and engages a stud 40 on the interrupted gear control cam 41 whereby the gear is moved into mesh with the pinion 42 and the record changing cycle commences.

By the improved mechanism it will be appreciated that when the trip control lever 1 is tilted and the friction pad 16 removed from friction lever arm 17 the drive is disconnected and any movement or pressure on the trip control lever caused by its engagement with the rotating upper cam 6 cannot be transmitted back to the stylus. This is of importance as the trip control lever 1 thus becomes isolated from the rest of the automatic mechanism and the work which is done during this tilting movement cannot damage the pick-up or record through side pressure on the stylus.

Figures 7 to 9 illustrate the invention as applied to an auto stop mechanism and turntable brake. The trip control lever 44 is constructed and mounted as in the previous form and is actuated in its trip operation by the cam member 45 having side and upper cam surfaces. The free end of the lever 44 lies beneath the cranked arm 46 of a trip rod 47 pivoted in the fitting 48 to move about a horizontal axis. The other end of the trip rod 47 has an upstanding portion 49 which engages in an aperture 50 in an arm 51 of a trip lever pivoted on a vertical axis 52. The other arm 53 of the trip lever is provided with a shoulder 54 against which the end 55 of a catch lever 56 is adapted to engage during the playing of a record.

The catch lever 56 is pivoted on a vertical axis 57 and is operatively connected to an arm 58 which carries a switch contact 59 which is adapted to open or close a switch 60 in the motor circuit.

The catch lever 56 carries a brake pad 61 for braking the turntable 62 when the contact 59 opens the switch. The shoulder 54 and end 55 of catch lever 56 are held in engagement by a spring 63.

The pick-up arm 64 is operatively connected to an auto stop lever 65 having a pin 66 adapted to contact the slotted arm of a delay lever 67 which is pivoted in a vertical axis 68 and is connected by a pin and slot connection 69 to one arm of a pivoted friction lever 70. The other arm of the friction lever 76 is engaged by the friction pad 71 of the trip control lever 44 to provide a releasable friction drive to the lever 44.

The auto stop lever 65 has an extension 2 adapted to engage a pin 73 on the catch lever for resetting the trip lever 51, 53 when the pick-up arm 64 is moved outwardly to place the stylus in position to play a new record, and to close the motor circuit.

In the case of a phonograph having a spring drive the arm 58 will be unnecessary and the trip control lever 44 will control the turntable brake only.

I claim:

1. In a phonograph incorporating a pickup which moves from a starting position respectively across a playing groove and into a runout groove of a record being played, and a mechanism for initiating the return of the pickup to its starting position after the latter has entered the runout groove; a trip device mounted for oscillative displacement within and angular displacement relative to a plane surface disengageable connection means, means connecting said trip device in driven relationship with said pickup for unidirectional displacement thereby in said plane during movement of the said pickup across the playing groove, said connection means being disengaged by such annular displacement of said trip device relative to such plane surface, further means having one element thereof operatively associable with said trip device to periodically displace said trip device during its planar movement in a direction opposing that imparted thereto by the pickup, and having another element operatively associable with said trip device when the pickup enters the runout groove, to angularly displace said trip device to disengage said connection means and to move said trip device into operable association with said mechanism.

2. A phonograph in accordance with claim 1, wherein said mechanism is spring-biased for actuation, and is normally latched against actuation, and said trip device upon being angularly displaced, unlatches said mechanism.

3. A phonograph in accordance with claim 1, wherein said mechanism is spring-biased for actuation, a latching member is positioned to restrain said mechanism against actuation by its spring, and said trip device upon being angularly displaced displaces the latching member away from its restraining position.

4-. A phonograph in accordance with claim 1, wherein the trip device is loosely pivoted at one end on a pivotal member and its pivotal end is provided with a short arm which is slotted to engage the pivotal member, the main portion of the trip device having a circular pivot hole whereby the trip device upon being operatively associated with said means is tiltably displaced upwardly about its pivotal end.

5. A phonograph in accordance with claim 1, wherein the trip device is pivoted at one end and its free end is provided with a cam surface which is engaged with a cam surface on said further means to effect a tilting movement of the trip device out of driven connection with said pickup and into connection with said mechanism.

6. A phonograph, in accordance with claim 1, wherein the movement of the trip device to break the drive between the pickup and the trip device is efiectuated by the tilting of the trip device by a cam surface carried on said further means, and wherein the tilting movement of the trip device causes the engagement of the trip device with a member operatively connected with a latch lever which is released thereby and a spring biased impulse lever is actuated upon release of the latch lever to initiate a driving connection to a rotary cam forming a part of said mechanism.

7. In a phonograph incorporating a pickup which moves from a starting position respectively across a playing groove and into a runout groove of a record being played, and a mechanism for initiating the return of the pickup to its starting position after the latter has entered the runout groove; a trip device for initiating the operation of said mechanism and normally unconnected therewith, said trip device having an element displaceable from one position in one horizontal plane to another position in a different horizontal plane, said trip device being connectible in frictional driven relationship with said pickup for displacement thereby along one horizontal plane as the pickup moves across the playing groove of the record when said element is in the one position and disconnected from such frictional driven relationship when said element is in the other position, said trip device being operably associated with said mechanism only when the element of the trip device is in the other position, and means operatively associable with said element and actuable only when the pickup enters the runout groove of the record to displace said element from the one to the other position.

8. A phonograph in accordance with claim 7, wherein said means comprising a member formed with a pair of surfaces in difiierent planes and having one surface periodically contacting with said element to move the latter in an opposing direction, in the plane of movement imparted thereto by the pickup when in frictional driving relationship therewith, thereby to neutralize the movement in the one direction of said element, and having a second surface contactable with said element to tiltably displace the same from its one position only when the pickup enters the runout groove.

9. A phonograph in accordance with claim 7, wherein said means comprises a rotating member having a pair of sloping cam surfaces, one cam surface being in periodical contact with said element to move the latter in an opposing direction, in the plane of movement imparted thereto by the pickup when in frictional driving relationship therewith, thereby to neutralize the movement in the one direction of said element, and the other cam surface being contactable with said element for displacing said element from its one position only when said pickup enters the runout groove.

10. In a phonograph incorporating a pickup which moves from a starting position respectively across a playing groove and into a runout groove of a record being played, and control mechanism for the phonograph operable when the pickup moves into the runout groove; a trip device mounted for oscillation within and angular displacement relative to a plane surface, disengageable connection means connecting said trip device in driven relationship with said pickup for displacement therein in said plane during movement of said pickup across the playing groove, said connection means being disengaged by such angular displacement of said trip device relative to said plane surface, further means having one element thereof operably associable with said trip device to periodically displace said trip device during its planar movement in a direction opposing that imby the tilting of the trip device by a cam surface carried on said further means, and wherein the tilting movement of the trip device causes the engagement of said trip device with a trip rod operably connected with a trip lever, which latter actuates a brake for braking the turn table carrying the record.

12. A phonograph in accordance with claim 10, wherein the movement of the trip device to break the drive between the pickup and the trip device is efiectuated by the tilting of the trip device by cam surfaces carried on said friction means, wherein the tilting movement of the trip device causes the engagement of said trip device with a trip rod operably connected with a trip lever, which latter actuates a brake for braking the turn table carrying the record, and wherein the tilting of the trip lever also causes the opening of a switch in the motor circuit.

References Cited in the file of this patent UNITED STATES PATENTS 1,715,873 Stockton June 4, 1929 2,211,423 Hokanson Aug. 13, 1940 2,392,111 Alexandersson Jan. 1, 1946 2,520,251 Mullaney Aug. 29, 1950 2,545,360 Johnson Mar. 13, 1951 2,568,496 Hall Sept. 18, 1951 2,571,466 Metcalfe et al. Oct. 16, 1951 

